JPH04185894A - Auxiliary method of shield tunnel joining section - Google Patents

Abstract

PURPOSE:To make it possible to execute with high degree of accuracy by inserting a rod with high pressure water from the first high pressure water injection nozzle, and pouring ground hardner to the ground crushed with high pressure water and compressed air from the second nozzle and air nozzle from a pouring nozzle. CONSTITUTION:A rod 4 is rotated with column machine and, at the same time, the ground is cut while injecting high pressure water from the first high pressure water injection nozzle 8, and it is cut with the front bit 13 to insert the rod 4 into the ground. After that, a ball valve 12 is set to close the nozzle 8, the rod 4 is rotated to withdraw, and super-high pressure water and compressed air are respectively injected from the second high pressure water injection nozzle 9 and air nozzle 10 to crush the poured ground in advance while withdrawing the rod 4. Then, ground hardner is poured from a pouring nozzle 11 of the ground hardner to a crushed part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an auxiliary construction method for shield tunnel joints in shield construction.

[Conventional technology]

In order to connect shield tunnels underground without forming a reaching shaft, the shield tunneling machines should be moved as close as possible to each other,
Work such as digging and connecting the gaps by hand will be required.

In order to carry out work such as excavation and concrete covering, which is different from normal shield work, it is necessary to improve the surrounding ground.

Conventionally, such ground improvement has been carried out as an auxiliary method for shield construction using chemical injection methods, freezing methods, etc.

As is well known, the chemical injection method aims to solidify the soil particles by injecting a coagulant such as water glass between the soil particles in the ground.

In addition, the freezing method works by freezing the moisture contained in the ground, solidifying the soft ground with standing water and preventing water from springing up, and then unfreezing it after the work is completed. This is a construction method that returns the soil to its original state, by driving a freezing tube into the ground and circulating a refrigerant such as calcium chloride solution or liquid nitrogen inside the freezing tube to freeze the soil from the surrounding area.

(Problem to be solved by the invention) In this ground improvement method using chemical injection method, injection pressure is applied, so underground objects (structures)
If it is near the connection, the injection pressure may have an adverse effect on the structure.

In addition, in construction from the ground, if the tunnel depth is large, drilling accuracy is a problem, and the drilling accuracy tends to be poor, making it difficult to obtain reliability of the ground improvement body.

On the other hand, if construction is attempted from inside the shield tunnel, the injection pressure may have an adverse effect on the segment.

In the freezing construction method, the ground tends to rise due to freeze expansion and subsidence during thawing, and depending on the soil quality, compaction pressure due to frost heave may also act.

When constructing the shield from underground using this freezing method, even if radial freezing pipes are installed, it will not be effective unless construction is done simultaneously from both tunnels to be joined, and depending on the construction angle, pipes may be required for attachment. , is extremely troublesome. Furthermore, compared to methods such as chemical injection, it takes longer and costs more.

The present invention eliminates the disadvantages of the conventional auxiliary construction methods, and provides an auxiliary construction method for shield tunnel joints that can be performed from inside the shield tunnel with high precision, in a short time, and easily.

[Means to solve the problem]

In order to achieve the above object, the present invention forms an insertion hole in the skin plate or segment of a shield tunneling machine, and includes a compressed air injection pipe as an outer pipe, a high pressure water pipe as a middle pipe, and a soil hardening material as an inner pipe. It is a triple tube rod consisting of an injection pipe and a first high-pressure water jet nozzle that communicates with the high-pressure water pipe on the tip surface of the acid rod, and a first high-pressure water jet nozzle that communicates with the high-pressure water pipe on the side of the tip of the rod, and that communicates with the high-pressure water pipe and emits high-pressure water. A second high-pressure water jet nozzle whose jetting is switched between the first high-pressure water jet nozzle and the compressed air injection pipe by a valve in the pipe and an air nozzle communicating with the compressed air injection pipe are provided adjacent to each other, and the second high-pressure water jet nozzle and the air nozzle are connected to each other. A rod for column jet grouting with a soil hardening material pouring nozzle opened at a position slightly away from the shield hole is inserted into the ground at an arbitrary angle through the insertion hole of the skin plate or segment. High-pressure water for cutting is ejected from the high-pressure water ejection nozzle, the rod is inserted to a predetermined length, and then the ground is injected with high-pressure liquid and compressed air injected from the second high-pressure water ejection nozzle and air nozzle on the side of the rod tip. By crushing the ground in advance, and then pouring out a soil hardening material from a soil hardening material pouring nozzle into the crushed portion, an improvement body is created in the ground, and the insertion hole for the skin plate or segment of the shield tunneling machine is The inside of the box is surrounded by a water stop box to which the forced slime collection pipe is connected, and the rod for the column jet grouting method is passed through the insertion hole provided with the packing of this water stop box and then passed through the insertion hole. This is a summary.

[Effect]

According to the present invention as set forth in claim 1, the column jet grouting method is carried out from inside the shield pit, and as a result, the grouting can be carried out without applying high injection pressure as in the chemical injection method. The ground can be improved without any negative impact, and only the necessary areas can be improved with precision.

According to the present invention as set forth in claim 2, in addition to the above-mentioned effects, slime can be efficiently processed in the water stop box.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view showing one embodiment of the auxiliary construction method for shield tunnel joints of the present invention, in which 1 is a shield excavator, 2 is
is a segment assembled inside the tunnel, and shield tunnels are constructed to face each other, and these are connected.

A column machine 3 is installed in the shield pit, and a triple-pipe rod 4 is set to the column machine 3 so as to be rotatable and movable back and forth so as to be propelled horizontally or at any angle.

FIG. 3 shows the details of the triple-pipe rod 4, which includes an inner pipe for injection of soil hardening material 5, a middle pipe for high-pressure water pipe 6,
It consists of a compressed air injection pipe 7 which is an outer pipe, and the vicinity of the root of the rod 4 is rotatably and propellably held by the chuck device of the column machine 3. Although not shown, the end of the rod 4 a ground hardening material supply port communicating with the ground hardening material injection pipe 5; an ultra-high pressure water supply port communicating with the high pressure water pipe 6;
and a compressed air supply port communicating with the compressed air injection pipe 7, which are respectively connected to a grout pump that receives material supply from the grout mixer, and a grout hose.
The ultra-high pressure hose connects to the ultra-high pressure pump that supplies water from the water tank, and the air hose connects to the compressor.

On the other hand, a first high-pressure water jet nozzle 8 communicating with the high-pressure water pipe 6 is formed at the tip end of the rod 4, and a second high-pressure water jet nozzle 8 communicating with the high-pressure water pipe 6 is formed at the end side of the rod 4. A nozzle 9 and an air nozzle 10 communicating with the compressed air injection pipe 7 are provided adjacent to each other, and a soil hardening material pouring nozzle 11 is opened at a position slightly apart from the second high-pressure water jetting nozzle 9 and the air nozzle 10. did.

A ball valve 12 for switching the jetting between the first high-pressure water jet nozzle 8 and the second high-pressure water jet nozzle 9 is provided inside the high-pressure water pipe 6.

If a valve seat is provided in advance, this ball valve 12 can be formed by simply inserting a steel ball into the high-pressure water pipe 6 when necessary, but it is also possible to open and close it by electrical control instead of using a solenoid valve. .

Furthermore, the first high-pressure water is applied to the distal end surface of the rod 4.

Around the jet nozzle 8, there is a tip focus 1 made of a carbide tip.
3 was established.

An insertion hole 14 is formed in the skin plate 1a of the shield excavator 1 by cutting with this tip bit 13 or the like.

The inside of the insertion hole 14 is surrounded by a water stop box 15. This water stop box 15 is a steel box with the insertion hole 14 open, and is attached to the skin plate 1a by welding. The insertion hole 1 is provided with a double packing of an outer packing 16a and an inner packing 16b on the periphery.
7, and a forced slime recovery pipe 18 was connected to the side by flange connection.

In this way, the rod 4 for the column grouting method set in the column machine 3 is inserted into the insertion hole 17 of the water stop box 15 in which the gaskets 16a and 16b are provided.
It passes through the insertion hole 14 and is inserted into the ground.

This rod 4 is rotated and propelled by the column machine 3, and at this time, the ground is cut while spouting high-pressure water for cutting from the first high-pressure water jet nozzle 8, and the cutting is performed by the tip bit 13. will also be done.

These cuts are for inserting the rod 4, and it is sufficient if a hole approximately the diameter of the rod 4 can be formed.

Then, the rod 4 is inserted into the ground to a predetermined length.

This rod 4 can be added to the length along the way, and a predetermined length can be secured by appropriately adding one piece to the length that can be carried into the tunnel.

Next, the ball valve 12 is set to close the first high-pressure water jet nozzle 8, and while the rod 4 is rotated and pulled back by the column machine 3, the second high-pressure water jet nozzle 9 on the side of the tip of the rod 4 is connected. Ultra-high pressure liquid and compressed air are injected from an air nozzle 10 to crush the injection ground in advance, and then a cement milk-based ground hardening material is poured into the crushed portion from a ground hardening material pouring nozzle 11.

In this way, as shown in FIG. 1, a columnar solid body 19 is created as an improved body in the ground.

If the air volume or pressure from the air nozzle 10 is increased, the slime will be discharged toward the base of the rod 4 due to the air lift effect and enter the water stop box 15, so the slime will be collected here and the slime will be forced. It is efficiently collected by the collection pipe 18.

By the way, the columnar solid bodies 19 are formed in the required number around the tunnel in an umbrella shape by repeating the same operation, and the solid bodies 19 cross the tips of the shield tunnels that are connected to each other. If this is done, the periphery of the joint will be surrounded by columns of the solid bodies 19, and the desired ground improvement will be achieved.

In addition, although not shown in the drawings, as another embodiment, the insertion hole 14
is formed in segment 2, and segment 2
The rod 4 may be inserted into the ground by penetrating it.

In that case, since the angle of the rod 4 will be closer to horizontal than in the previous embodiment, a long rod 4 will be sufficient as the connecting piece.

In order to form the insertion hole 14 in this segment 2, it is effective to remove a part of the segment 2 after assembly or to use a segment with a hole provided in advance.
Setting the water stop box 15 inside is the same as in the previous embodiment.

〔Effect of the invention〕

As mentioned above, the shield tunnel joint auxiliary construction method of the present invention can be constructed from inside the shield tunnel, so it can be carried out more accurately, in a shorter time, and more easily than when it is carried out from above ground, reducing the construction period and cost. This can contribute to savings.

In addition, unlike the chemical injection method, injection pressure is not applied, and unlike the freezing method, there is no ground uplift or subsidence, so improvements can be made without affecting underground structures or segments. It is something that can be done.

[Brief explanation of the drawing]

Fig. 1 is a side view showing one embodiment of the auxiliary construction method for shield tunnel joints of the present invention, Fig. 2 is a longitudinal sectional side view of the main part of the same, and Fig. 3 is a longitudinal sectional side view of the tip part showing details of the rod. , FIG. 4 is a front view of the same as above. ■...Shield excavator 1a...Skin plate 2...Segment 3...Column machine 4.
・・Rod ・・Ground hardening material injection pipe 6・
...High pressure water pipe 7...Compressed air injection pipe 8...
・First high pressure water jet nozzle 9... Second high pressure water jet nozzle 10... Air nozzle 11 River soil hardening material pouring pipe 12... Ball valve 13... Tip bit 14... Insertion Hole 15...Water stop box 16a...Outer packing 16b...Inner packing 17...Insertion hole 18...Slime forced collection pipe 19...Solid body

Claims (2)

[Claims] (1) An insertion hole is formed in the skin plate or segment of the shield tunneling machine, and a compressed air injection pipe as an outer pipe,
A triple pipe rod consisting of a high-pressure water pipe as a middle pipe and a soil hardening material injection pipe as an inner pipe, and a first high-pressure water jet nozzle communicating with the high-pressure water pipe is formed on the distal end surface of the rod, Further, at the tip end side of the rod, a second high-pressure water jet nozzle, which is connected to a high-pressure water pipe, and whose jetting is switched between the first high-pressure water jet nozzle and the first high-pressure water jet nozzle by a valve in the high-pressure water pipe, and an air nozzle, which is connected to the compressed air injection pipe, are connected in close proximity. A rod for the column jet grouting method with a soil hardening material pouring nozzle opened at a position slightly away from the second high-pressure water jetting nozzle and the air nozzle is inserted through the insertion hole of the skin plate or segment. Insert the rod into the ground at an arbitrary angle from inside the shield mine, and insert the rod to a predetermined length while spouting high-pressure water for cutting from the first high-pressure water jet nozzle, and then the second high-pressure water jet from the side of the rod tip. The injection ground is crushed in advance by high pressure liquid and compressed air injected from the nozzle and air nozzle.
An auxiliary construction method for shield tunnel joints, characterized in that an improved body is created in the ground by pouring out a soil hardening material from a soil hardening material pouring nozzle into the fractured part. (2) The insertion hole of the skin plate or segment of the shield tunneling machine is surrounded by a water stop box to which the forced slime recovery pipe is connected, and the rod for the column jet grouting method is equipped with the packing of this water stop box. Claim 1: Passing through the insertion hole after passing through the insertion hole.
Supplementary construction method for shield tunnel joints as described in section.